Research targets gluten-free products

Aug 20, 2010

People readily identify Kansas as "the wheat state," but may not realize that the state also is a leading producer of sorghum, a grain crop that could become a key ingredient in developing healthful food products for millions of people who are sensitive to wheat gluten.

In the United States, sorghum currently is grown primarily as an animal feed, said Scott Bean, a U.S. Department of Agriculture (USDA) research chemist. He's based at the Center for Grain and Animal Health Research operated in Manhattan, Kan., by USDA's Agricultural Research Service (ARS).

Sorghum is rich in disease-fighting nutrients (plant-based phytochemicals and antioxidants are examples), and is used as a human food source for 35 percent to 40 percent of the world's population, Bean said.

In Africa and Asia, for example, sorghum is a key ingredient in porridges and flat breads.

It also is a gluten-free grain, said Bean, who is researching potential applications in the rapidly expanding market for gluten- free food products. About one percent of the population worldwide is thought to suffer from sensitivity, either an allergy to or intolerance for, wheat gluten.

While gluten-like proteins present in other grains (rye and barley are examples) are closely related to wheat (and are also toxic for people with Celiac disease), wheat gluten is commonly the most widely used and, thus, the most common offender, Bean said.

Three million Americans are thought to suffer from the autoimmune disorder, which is called Celiac disease (or Celiac sprue).

The disease causes an inflammation of the small intestine and interferes with the absorption of nutrients. It tends to run in families, affects children and adults, and can present in a variety of symptoms including abdominal pain, bloating, acid reflux, chronic constipation, headaches or unexplained weight gain or loss, and that's why it often is undiagnosed -- or misdiagnosed.

Damage from the sensitivity to gluten is cumulative and, while there presently is no cure for Celiac disease, it can be treated successfully by choosing a gluten-free diet and lifestyle, Bean said.

Research on the disease and its effects is ongoing, and development of health-promoting gluten-free products expanding, said Bean, who explained that in 2006, U.S. gluten-free products accounted for $700 million in sales (Source: Gourmet Retailer 2006); in 2010, gluten- free products are expected to yield $1.7 billion in sales (Source: Gourmet Retailer 2006).

To understand the growing product market and its potential implication in helping to offer healthful food choices and support new uses for Kansas' crops, it's important to understand the role of gluten, which is a collective term for a group of proteins that store nitrogen in the nutritive tissue (endosperm) of the grain, Bean said.

In bread making, wheat gluten provides the structure to hold gas that gives the bread its light, airy texture -- gluten proteins are largely responsible for making bread, bread, said Bean, who noted that developing appealing and nutritious breads without gluten is challenging.

Historically, he said, gluten-free wheat breads and bread products have suffered from lack of taste, texture and quality.

In focusing on milling and refining white sorghum flours and their potential as a bread base, Bean noted that white sorghum also has a relatively neutral taste that makes it possible to introduce proteins derived from a non-wheat source to enhance bread making (without wheat and wheat gluten).

"Think about it," Bean said: "Corn chips are made from corn and have a definite corn flavor, which is good in a product like that. The distinct corn flavor is not typically desirable in products such as white pan bread.

Milling white sorghum (which is gluten-free) and introducing other celiac-safe proteins such as those isolated from corn or carob germ flour that improve the functionality of gluten-free flours can, however, be used to create a flour that has somewhat similar functionality as wheat flour and makes flavorful tortillas and breads."

Bean is currently collaborating with scientists at Kansas State University on researching milling processes for white sorghum and bread formulas with gluten derived from isolated corn or carob germ flour proteins, which is less expensive than the isolated corn proteins.

The research focus also includes binding agents, such as xanthum gum (which often is listed on nutrition labels on food products) to thicken the bread dough and hold gas, which adds volume, Bean said.

"The research is promising," said Fadi Aramouni, K-State Research and Extension food scientist who is sought after for his expertise in developing new food products.

Aramouni, who is collaborating with Bean on research for the new grain products, acknowledged that gluten-free breads have been compared to cardboard.

We need to do better than that, said Aramouni, who, to date, has worked to develop a shelf-stable, sorghum-based waffle mix that is free of wheat gluten, and also free of eggs and milk (which also are potential allergens) for an international resort.

Aramouni, who teaches a new food product research and development class for upper level food science students, also has challenged students to come up with new products, which have included a sorghum- based, gluten-free waffle-style ice cream cone that earned a national award.

"The expansion in gluten-free product development is targeting health, but it also stands to provide opportunities for ag producers," he said. "And, in collaborating with researchers such as Scott Bean, we also can work toward providing health-promoting foods for the general population and the millions of people worldwide who have special needs."

Collaborations between the food scientists (at K-State) and research chemists (at the USDA-ARS center) expand the resources, said Bean, who noted that Kansas State University's Departments of Agronomy and Grain Science and Industry (both in the College of Agriculture) are innovative grain research centers.

The Great Plains Sorghum Improvement and Utilization Center is, for example, based in K-State's Dept. of Agronomy and offers a platform for K-State faculty, USDA-ARS scientists and researchers from Texas A&M and Texas Tech to collaborate on all aspects of sorghum research and education from production, genetics, food processing and bioenergy production. More information about the center is at www.agronomy.ksu.edu under research section.

"We want to take a leadership role," said Aramouni, who, as a career food scientist acknowledged that the research offers challenges -- and opportunities."